Grodecki and Lillich both
concur with Hucher's suggestion that this window was a donation of the
Abbey of St Calais, which (like the Abbeys of Evron and St Vincent, who
are supposed to have donated the windows in bays 105 & 111 respectively)
fell within the diocese of Le Mans.

St Calais (aka Carilefus or
Calevisus) was a 6th century hermit saint who doesn't make it into the
Golden Legend but whose life was described in the Vita Carileffi. The
Abbey of Anisole, built on land supposedly donated for the purpose by
King Childebert, was later re-dedicated in honour of its founding saint.

Both the founding Charter
and the Vita that were held in the Abbey are later forgeries (probably
created in the 9th century by the clergy at Le Mans to substantiate their
claim over the Abbey) but the foundation myth itself is highly credible,
given the number of more reliably documented cases of Merovingian kings
parcelling out land willy nilly to anyone who took their fancy [For Merovingian
generosity see John Michael Wallace-Hadrill, "The Long Haired Kings",
Methuen 1962. For the background to the forged foundation charter/vita
and the associated 9th century ownership disputes, see Susan Wood, "The
Proprietary Church in the Medieval West", OUP, 2006, p.219ff].